Insulating material.



WILLIS EUGENE EVERETTE, 0F TACOMA, WASHINGTON.

INSULATING MATERIAL. I

Specification 0! Letters Patent.

Patented Oct. 20, .1908.

Application medley 17, 1996'. Serial No. 317,848.

To all whom it-may concern:

Be it known that. I, WILLIs EUGENE EVER- Errn, a: citizen'of the United States, and a resident of Tacoma, in the county of Pierce and State of Washington, have invented certain new and useful Improvements in Insulating Materials, of WhlCh the following is aspecification. p

My invention consists of taking pure materials-(lime, quartz, and alumlnum) and making a definite thermo chemical nonoxidizable, non-combustible, and non-electricalconducting filamentary compound of? pure bi-silicate of calcium and aluminum, to

be thereafter spun into threads. Although:

magnesia oxid, or carbonate, or silicate, may be used-or even strontium caesium, or any alkaline element in place of calcium, I prefer to use the latter, as hereinafter explained.

The so-called mineral wool that is made from blast .furnace slags is invariably made from impure materials, and is always of indefinite chemical composition, by reason of it containing-1mexcess of slllca and-- more or less-soda and" potash. This makesthe mineral wool or spun glass too brittle to be of any filamentary use, and also renders it easily oxidizable tothe action of! heated waters and heated moisture.

All substances andcompounds hitherto invented that. contain spun glass or mineral wool are either impure, and chemically indefinite compounds of mineral wool threads coated with rubber, cotton, or silk; or, such inventions have for solid mineral wool mixed with a soluble alkaline silicate, (such as thesilicafies of potash or soda) to bind the mass to 't er.

, y inventiomisfor a water-- proof, fibrous compound of filaments of pure bi-silicate of calcmm and aluminum, to be thereafter spun into threads, so as to make a fibrous and flexible-cloth ofglaSs-c'. e..--

a. non-electrical conducting, non-oiidizing,

insoluble, water-proof and eproof clot-h of glass both with and withoutbei'ng with a. paste-like, colloid or jelly hke form of muscovite, or mica precipitated from an acid solution by an alkali.

The object ofmy invention, is to provide.

a new kindv of insulating material, which, by reason ofits complete freedom from carbon, avoids the inflammable and destructible character of tar, rubber, silk, linen, cotton,

asphalt, and other carbon electrical insulacoated tions, and which also, by reason of its com.- plete freedom from soluble alkalies, avoids the gradual deterioration and disintegration of glass, porcelain, asbestos and other vitreous or clay electrical insulations.

When a sub-marine cable or other cable or wire intended for electric transmission of telegraphic or "telephonic messages, or for the transmission ofpower for electric lighting, heating, or other purposes, is covered or coated with my improved insulating material, it will be found that perfect insulation is afforded, and that currents of enormous energy can be sent along a wirewithout danger; there being-nothing to burn, nothing to melt, nothin to break. The most efiicient protection Wlll be afforded by applying this msulatingmaterial directly to the copper or other metallic wire, because when the wire has been previously wound with silk, cotton, asbestos, tar or other substance, the transmission of a current of suflicient energy to burn, melt or otherwise destroy such intermediate coverings, will of course, impair such intermediate covering without however affecting the outer covering of my improved insulatingvmaterial.

- hile various methods might be employed to make this im roved insulating material which may be briefly and broadly spoken of as a flexible, tenacious, and insoluble composition of bi-silicate of calcium and aluminum, the method which I prefer is as fol- 'lows:-I select some form of lime-stone which is as nearly as possible simple car'- bonate of calcium, such as marble dust, which runs about 95 to 98 per cent. of calcium carbonate, the remainder being silica or quartz. In selecting the lime-stone for my improved insulating material, it is important to avoid the common lime stone of the blast furnace and all forms in which feldspar is present, because, when converted into a composition designed for my improved insulating material, there would be present in addition to the insoluble bi-silicate of calcium and aluminum, soluble silicate of soda and potash, which to the extent of their quantity, would defeat the purpose and efiect of my improved insulating material. Instead of limestone (a carbonate) I may use the proper corresponding quantityfof pure lime, (or calcium oxid,) since the carbon dioxid leaves the limestone in'any case, at the temperature of combination or incandescent heat, and this is below the temperature at which the reaction begins for the combination to unite. Having then secured the desired quantity of this marble dust, I mix it up with finely powdered quartz, and finely powdered metallic aluminum. The preferable proportions are 30 parts marbledust, 30 parts quartz, and 40 parts aluminum. The metallic aluminum may, if prefered, have been ground into a fine powder, by first heating it to about 800 degrees Fahrenheit, at which temperature it becomes extremely brittle and easily crushed. This mixture is heated to about 3,000 degrees Fahrenheit, when it becomes a thin liquid which is bi-silicate of calcium and aluminum, the carbonate of calcium being broken down, and the carbon and excess of oxygen being driven ofl in gaseous form. This molten bi-silicate of calcium and aluminum, is then blown by jets of air or steam in any Well known and usual manner into long,

fine, threads, which when cooled will befound to have remarkable tenacity and flexibility so that they can be readily handled, twisted or spun into threads or cords of uniform size, and woven into compact sheets or bands like linen, or silk threads, and when so woven, can be wrapped around wires, cables or any other things which it is desired to insulate. The insulating material thus prepared, may be used with great effect without further treatment or protection, and when so used, will have all of its normal insulating permanent water-proof and fire-proof character; but to avoid the access of moisture to the line-wire through the interstices between the threads, Whether one or more layers of this woven material is employed, and to avoid the leakage of electricity through said interstices, it is preferable to provide, either inside or outside the wrappings of insulating material, some substance impervious to moisture and of poor conductivity. Instead of such substance however, I prefer to coat this insulating material with white mica, commonly known as muscovite. To effect this coating I pulverize the mica, and dissolve it to a condition of jelly-like paste, by boiling it first in pure nitric acid for about an hour, and then add pure hydrochloric acid and boiling and evaporating to the paste-like condition. Thin with water until the whole is held in suspension, after which, by the addition of concentrated hydrate of ammonia, a very slimy, gelatinous and adhesive precipitate is formed, which can be applied to the insulating material as paint mechanically or by dip ing. I may use recognized substitutes r the materials above specified such as magnesium or strontium, for calcium; but I have found that a combination of calcium, aluminum, silicon, and oxygen, seem to give filaments possessing in the greatest degree the qualities desired.

I claim 1. An insulating material formed of insoluble, tenacious, flexible, fireproof, filamentary threads, composed solely of a combination of calcium, aluminum, silicon, and oxygen.

2. An insulating material formed of insoluble tenacious, flexible, filamentary threads and filaments, composed of bi-silicate of calcium and aluminum, and coated with a solution of muscovite.

WILLIS EUGENE EVERETTE.

Witnesses ANNA VAN 

